We propose to devise procedures for the isolation, purification andeventual dissolution of the aerobic cell membrane from Rhodopsuedomas speheroides. Once this has been accompished whe then plan to characterize the protein components of this membrane species in order to determine if any of these protein species are found in the anaerobic cell membrane and in the chromatophore membrane system. At the present time we have been able to demonstrate using both protein chemistry and immunochemistry that better than 95% of the chromatophore membrane proteins are unique to the chromatophore. However, there is eveidence to suggest that of the remaining 5%, there may prove to be identity between specific aerobic and anaerobic membrane proteins. Such a determination will then enable us to investigate precursor-product relationships under a variet of environmental conditions between all chromatophore proteins and other cellular components. These studies coupled with the use of macromolecular mutants, in vivo kinetic experiments and in vivo density shift experiments should provide us with a sound experimental basis for understaning the development, synthesis and regulation of chromatophore specific organelles. Bibliographic references: Topology and Growth of the Intracytoplasmic Membrane System of Rhodopsuedomonas speroides: Protein, Chlorophyll, and Phospholipid Insertion in Steady-State Anaerobic Cells. M.H. Kosakowski and S. Kaplan. J. Bacteriol. 118:1144-1157 (1974).